The pre-Columbian Mesoamerican civilizations, including the
Nahuatl-speaking ones, did not have an alphabet, properly speaking; they used different kinds of
more-or-less
ideographic writing.
(For further information about
pre-Columbian writing see Kevin
Callahan's web pages on Mesoamerican
writing systems.)

The Nahuatl
orthographies developed in the sixteenth century and since then
have, naturally enough, usually been based on the Spanish writing system. For the majority of the Nahuatl
phonemes, the
correspondences were unproblematic, but for others there have been differing customs among those who have
written Nahuatl.

These notes are by no means exhaustive, especially in regard to the writings of classical and colonial times;
they only deal with some of the more common variations.

Vowels

The short vowels have always been written as in Spanish (a,
e,
i,
o).
The vowel /o/
is sometimes written u when its pronunciation
approaches that of Spanish /u/.
Length
has typically gone unrepresented. When
it has been written, the most common convention has probably been the use of the
macron
(ā,
ē,
ī,
ō). We follow that convention in these electronic pages.
Sometimes, for typographical reasons, the
circumflex
(â,
ê,
î,
ô)
or the dieresis
(ä,
ë,
ï,
ö)
has been used instead, and sometimes double vowels have been written
(aa, ee, ii, oo).

c when preceding a back vowel or a consonant, and qu
when preceding a front
vowel (e.g.: can and quen are /kan/ and /ken/), or k in all
cases.

kw

cu (or qu when preceding a back vowel),
cuh (or uhc) in syllable final position; or ku; or kw.
Note that cuh is not a syllable. Accordingly, although an incorrect
trisyllabic pronunciation is common, tecuhtli 'lord' has only two
syllables
CVC.CV /tekw.tƚi/.

y

y (sometimes i)

w

hu (in syllable initial position) and uh
(in syllable final position) (e.g.: Huauhtla is /wawtla/). Or, w in all cases, or u in all cases. Also written as b or v when labial. Also written as o in older
documents and names.
(For example, Oaxaca is /waxakan/.)

Not written, or written as
h, j, ',
or a grave accent mark (e.g.: à is
/aʔ/).

A number of Nahuatl languages permit a sequence of /l/ + /l/, which, naturally enough, is written ll. It appears in
words such as calli 'house' or tlaxcalli 'tortilla'.
This is not at all like the Spanish ll, which in Mexico is generally pronounced
[y];
rather it is a long
/l/ sound.
In some varieties of Nahuatl the length of this [ll] has been lost, and it is
pronounced and written as l: e.g. cali
'house' and tlaxcali 'tortilla'.
In other varieties it is pronounced [hl]
(and typically written jl) e.g. cajli 'house' and tlaxcajli 'tortilla'.